Unsigned byte: Java byte data type (0-255)?

Question

I need an "unsigned" byte type.
How can I implement a one byte data type with values from 0-255 in Java?

Answer 1

No there isn't an unigned byte, but you don't need
one. You just separate storage representation from
calculation representation. When you store the
"unsigned byte" you use a signed byte. When you make
calculations on the "unsigned byte" you use an
integer. For this you need two conversion functions,
public static int toInt(byte b) {
return b + 128;
public static byte toByte(int i) {
return (byte)(i - 128);
}These amazing functions must be tested off course.
public void testUnsigned(int unsgn) {
byte bA[] = new byte[1];
int i = unsgn;          // 0 to 255
bA[0] = toByte(i);    // stored as -128 to 127
int j = toInt(bA[0]); // 0 to 255
if (i==j)
System.out.println("Yes it works!");
Sorry, but your code doesn't work. I also tried the byte & 0xFF and I get strange results too. 0xFF transfer to 129, which (I think, but maybe I'm wrong) should transfer to 255 (0xFF == 1111 1111, no?). After some tests, I found that "ounos" solution is the best fitted (byte < 0 ? b+256 : b)
If you only do a (byte + 128), you'll get, for example:
0000 0000 (should be 0) == 128
I think that only 1 case is enough to proove that this code doesn't work... :-)